Copper

Category: inorganic

Written by WaterFilterMatch Editorial TeamApril 2026

EPA Action Level

1.3 mg/L

Status

EPA Regulated

NSF Standard

NSF/ANSI 53, NSF/ANSI 58

Health Effects

Short-term: gastrointestinal distress (nausea, vomiting, diarrhea). Long-term: liver damage, kidney damage. People with Wilson's disease are particularly sensitive.

Source: EPA National Primary Drinking Water Regulations

Where It Comes From

Corrosion of household copper plumbing systems, erosion of natural deposits. Copper is very common in residential plumbing installed since the 1960s.

Where It's Commonly Found

Homes with new copper plumbing (first 2 years) or acidic/soft water that corrodes pipes. Regulated via the Lead and Copper Rule (action level, not a traditional MCL).

Approximately 1.5–2% of U.S. households may have elevated copper levels. Exceedances trigger corrosion control treatment at the water system level.